textproduct: Rapid City

KEY MESSAGES

- A hot, dry, and breezy weather pattern is expected this week resulting in daily near-critical to critical fire weather conditions, worst today, Wednesday, and Thursday.

- A RED FLAG WARNING is in effect today for all of the western South Dakota plains; a dry cold front crossing the region will also result in a sudden gusty shift from south to northwest winds.

- The next real chance of precipitation holds off until Thursday, if not Friday, but includes the chance of thunderstorms and lightning which will continue to pose fire weather concerns.

UPDATE

Issued at 1053 PM MDT Sun May 10 2026

Low level southwest return flow will ramp up overnight through Monday morning ahead of a surface low north of Montana. This will bring well above-average temps to the region tomorrow. Highs will be near record levels across much of the western SD plains, especially along the interstate corridor and southward. The record highs at both UNR and KRAP are 95 (from 2025) so don't think those records will be broken. The big concern continues to be fire weather conditions. Will continue the Red Flag Warning where it is already issued.. The question is what to do with the Fire Weather Watch. Higher RHs across far NW SD and Quickly greening grasslands would hinder fire growth, but there are still dead fuels around. Additionally, while RH may not quite reach criteria, with gusty winds expected, especially directly behind the front will still support near-critical fire weather conditions. Will move forward with upgrading the watch to a Red Flag Warning after coordinating with neighboring offices. Also, will cancel the Fire Weather Watch for the Black Hills. While RFW criteria is not expected to be met due to weaker winds compared to the plains, fire weather conditions will still be elevated to near-critical. Cooler temps are expected Tuesday, with highs in the 70s...still 5-10 degrees above seasonal averages. Strong upper ridging will build across the region for midweek another round of hot temperatures. Temps on Thursday look similar to Monday. Elevated to potentially critical fire weather conditions will continue through Thursday.

DISCUSSION

(This Evening Through Sunday) Issued at 104 PM MDT Sun May 10 2026

Forecasted upper level ridging will bring back the dry and hot weather to the area.

Starting with tonight, continued northwest flow has kept the slight chances (10 to 20%) for light rain showers near the Black Hills for the rest of this afternoon. So far, any returns on the radar have been short lived, weak, and elevated. Rain chances diminish late this afternoon, overnight lows will be in the 40s, winds will remain on the lighter side at around 5 to 10 mph out of the east-to-southeast.

The heat is on tomorrow. Warm air will move into the area, driven by southerly winds, causing afternoon highs to reach the 80s and 90s. With low humidity and strong winds, fire weather is looking likely. Then, a passing cold front will swing winds to the west- to-northwest and cause winds to pick up speed. Gusts upwards of 30 to 40 mph are likely, high-end, isolated gusts near 45 to 50 mph are possible. As the front tracks over the Black Hills, isolated showers are possible, low end chances again due to lack of moisture, late Monday into Monday night.

Tuesday looks to be cooler, due to Monday's front. Highs will be back in the 70s with decreasing wind speeds through the day.

The rest of the week looks hot and breezy with highs back into the 80s to low 90s. Next chance for passing showers and storms is late Thursday into Friday. But these chances are low-end again.

AVIATION

(For the 12Z TAFS Through 12Z Tuesday Morning) Issued At 537 AM MDT Mon May 11 2026

VFR conditions are expected across the region today, but with increased wind compared to yesterday. Winds will start off out of the south-southwest, and then suddenly shift to northwest with passage of a cold front crossing the region from northwest to southeast between 11 AM and 8 PM depending on location. Current best prediction on timing for the wind shift is 17z/11am at KGCC, and 20z/2pm at KRAP. Most guidance keeps the front dry (perhaps some mid-level cumulus buildups) as does our official forecast, but it's worth noting a few CAMs have been hinting at a couple showers or a storm at times on some runs...either along or behind the front this afternoon into tonight. Confidence on development and placement is non-existent at this time and lack of moisture seems to be a solid limiting factor, but certainly something we'll keep an eye on if guidance trends toward more of a signal for this activity.

FIRE WEATHER

Issued At 104 PM MDT Sun May 10 2026

A near-critical to critical fire weather pattern is forecast to develop across western South Dakota starting Monday and continue through much of the week. The most critical days at this time appear to be Monday, Wednesday, and Thursday.

Upper level ridge will push very warm air into the plains, expected highs will reach the 80s to 90s. With no real push of extra moisture, relative humidities will drop to well below 20%. A passing front will kick wind speeds up. Ahead of the front, winds will be out of the south-to-southwest at around 10 to 20 mph. But as the front tracks through, winds will swing to the west-to-northwest at around 15 to 25 mph with gusts near 30 to 40 mph. Some high-end gusts could be even higher, nearing 45 mph.

With all that in mind, a Red Flag Warning has replaced the Fire Weather Watch for several counties in western SD. Other counties in western SD are still in the Fire Weather Watch.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Red Flag Warning from 11 AM MDT /noon CDT/ this morning to 9 PM MDT /10 PM CDT/ this evening for SDZ322>335. WY...None.